Astronomical chart



(No Model.) 5 Sheets-Sheet 1.

L. W. YAGGY. ASTRONOMIOAL CHART.

No. 556,486. Patented Mar. 17, 1896.

ANDREW 1010mm.Pumo-umowumummmc.

(No Model.) 5 Sheets-Sheet 2 L. W. YAGGY. ASTRONOMIGAL CHART.

No. 556,486. Patented Mar. 17, 1896.

SQLSTIOE.

WINT'E R. SOLSTICE SUMMER.

- (Nd Model.) I 5 Sheefis-Sheet 3'.

' L- W. YAGGY.

ASTRONOMIGAL CHART.

No. 556,486. Patented Mar. 17,1896.

W'L'fnesses MM (No Model.)

5 Sheets Sheet 4.

'LQW. YAGGY. ASTRONOMIGAL CHART.

Patented Mar. 1 1896-,

1 I 7 r i. L

5 SheetsSheet 5.

(No Model.)

L. w. YAGGY. ASTRONOMIGAL CHART.

,486.. Patented Mar. 17, 1896.

UNITED STATES PATENT OFFICE.

LEVI YAGGY, OF LAKE FOREST, ILLINOIS.

ASTRONOMICAL CHART.

SPECIFICATION forming part of Letters Patent No. 556,486, dated March 17, 1896. Application filed May 1, 1893. Serial N0. 472,598. (No model.)

To all whom it may concern.-

Be it known that I, LEVI WV. YAGGY, a citizen of the United States, residing at Lake Forest, in the county of Lake and State'of Illi-,

nois, have invented a certain new and useful Improvement in Astronomical Charts Illustrating the Seasons, which is fully set forth in the following specification, reference being had to the accompanying drawings, in which Figure 1 is a front elevation of one portion of the chart, showing the positionof the earth relative to the sun in March and September. Fig. 2 is the same view showing therelative position in June. Fig. 3 is the same View showing the relative position in December. Fig. 4 is afront elevation of the celluloid disk removed from the frame of the chart. Fig. 5 is a rear view of a portion of the chart. Fig. 6 is a transverse sectional view taken along the middle of that portion of the chart shown in the foregoing figures, looking downward. Fig. 7 is a front elevation of another portion of the chart, showing the position of the earth relative to the sun in each of the different months; and Fig. 8 shows a transverse sectional view of this portion of the chart taken at the line 8 8, looking downward.

The object of this chart is to indicate the relative position of the earth to the sun as it travels in its orbit around the sun, illustrating the inclination of the earths axis relativeto the sun.

One part of the chart is made movable, thereby changing the inclination of the earths axis relative to the sun, and another part of the chart illustrates the position of the earth relative to the sun in each month during the year.

My invention consists in the construction and operation of the different mechanisms composing the chart, showing the inclination of the earths axis as it travels in its orbit, whereby the changes of the seasons are illustrated, as hereinafter fully described and made the subject-matter of the claims hereof.

In the accompanying drawings, A is the frame of the chart, which I make preferably of thick pasteboard or other equivalent material.

, B is a celluloid plate pivoted at C. I print upon this celluloid plate a representation of through the frame of the chart'in an opening as large as the hemisphere. I also print on one margin of the celluloid plate the names of the months of the year, and Summer solstice and \Vinter solstice and the Equinoxes, as shown in full view in Fig. 4. There is an opening D in the chart through which the names of the months are exhibited as the celluloid plate is oscillated on the pivot O, and there are also openings E through which the other words are exhibited to show the summer and wintersolstices and the equinoxes.

F represents a slot cut in the frame of the chart through which a pin Gthat is attached to the celluloid disk B passes, and on which there is a thumb-piece H placed for the conthe world showing a hemisphere, which shows venience of oscillating the celluloid plate on its pivot.

I is an opening in the chart, in which there is a celluloid disk placed to represent the sun, which remains stationary. The opening D to exhibit the names of the months is between the representation of the earth and the sun. I place in the opening in the frame, through which the representation of the hemisphere of the earth is shown, a stationary celluloid disk or plate S, which is tinted in different colors to represent the different zones, which are indicated in the drawings by dotted lines. These zones always remain the same; but as the inclination of the earths axis is changed the different points on the earths surface vary in the different zones, so that when, for instance, the earth is in the position shown in Fig. 1, when the earths axis is directlynortlr and south, we have our equinox, and in June, when the north pole has its greatest inclination toward the sun, we have our summer solstice and south of the equator they have the winter solstice. When the north pole is at the greatest inclination from the sun,as shown in Fig. 3, we have the winter solstice and they have the summer solstice south of the equator.

In order to represent day and night upon the earth at the different seasons either one of two devices may be adopted. A partially opaque half-disk maybe placed back of S over that half of the disk farthest from the sun, or the opening in the frame of the cardboard which exhibits the earth may be made upon that half of the opening farthest from the sun only part way through-the said cardboard,--so that, by either construction, under the transmitted light with which this chart is to be used that half of the hemisphere toward the sun is lighter than the other half of it, indicatin g the portion of the earth which has the direct rays of the sun and showing that at the north pole there is perpetual night in December, while at the south pole there is perpetual day, and when the north pole has its greatest inclination toward the sun there is perpetual day at the north pole and perpetual night at the south pole.

When the axis of the earth has the inclination shown in Fig. 3, the days are short north of the equator and the nights are long, because the northern portions of the earth are brought into the sunsrays during a shorter period thanwhen the inclination of the axis to the sun isin the position shownin Flg. 2,

thus illustratingthe difference in the length.

of days and nights, or daylight and darkness, during the summer and winter solstices.

In Fig. 7, upon anotherportion of my chart, I represent by fixed celluloid disks B the position of the sun I andthe position of the axis of the earth relative to the sun during each month of the year as the earth travels in its orbit aronndthe sun. The axis of the earth always has the same inclination relative to the plane of the earths orbit, whichis' here the plane of the chart; but as the earth travels" in its orbit the inclination of the axis'is" from the sun when the earth is in oneposition inits orbit and toward the sun at another position, thus showing that the earthsaxis' always retains the same inclination to the plane of the earths orbit; butas the earth passes around the sun that inclination at one time will bring the north pole toward the sun, while at another time the north pole will be inclined from the sun, making the changesthat are illustrated by the movable disk of the chart above described. I print on the face of this portionof the chart the namesof each month, showing the inclination of the earths axis relative to the sun in these months, bringing the variouspositions of the earth,as shown fixed upon this portion of my chart, into correspondencewith the movable part B upon the other portion of the chart.

In Fig. (i I have shown a piece of thick paper 0 over the'front of the frame of the chart.

By this simple chart I illustrate the rela tive position of the differentparts of the earth to the sun during the diiferent months of the year, thereby indicating thechanges of the seasons and the difference inthe length of daylightanddarkness at different seasons of the year. IVhile the movable disk indicates that the inclination of the'axis of the earth changes from right to left or from left to right it is only a change relative to the sun as the earth passes in its orbit around the sun, as illustrated in Fig. 7 of the drawings, so that the illustration in Fig. 7 becomes important in connection with the movable or oscillating celluloid disk to show that the axis of the earth in its inclination to the plane of the earths orbit always remains the same,and the changes of the seasons is caused by the earth traveling in its orbit around the sun.

Having thus fully described the construction and operation of my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an astronomical chart, the frame A, provided with a circular opening, and with the openings, D and E; the transparent plate, B, pivoted to rotate about twenty-three degrees each side of its equinoctial position, and printed with a' representation of one hemisphere of theearth, so disposed as to show through the circular opening, and with words descriptive'of the seasons so disposed as to appear at appropriate intervals through the openings, D andE, astheplate, B, is rotated; and a representation of the sun, so placed as to be opposite the equator of the hemisphere when the same is in its equinoctial position.

2. In an astronomical chart, the frame A, provided with a circular opening, and with theopeningsD and E; the transparent plate, B, pivoted to rotate about twenty-three degrees each side of its equinoctial position, and printed with a representation of one hemisphere of the earth so disposedas to show through 'the circular opening, and with words descriptive of the seasons so disposed as to appear at appropriate intervals through the openings, D and E, as the plate, 13, is rotated; a representation of the sun so placed as to be opposite the equator of the hemisphere,

when the same is in itsequinoctial position;

and'an opaque background behind that half ofthe opening aforesaid farthest from the said representation of the sun.

3. In an astronomical chart, the frame A, provided with a circular opening, and with theopenings, D and E 3 the transparent plate,

13, pivoted to rotate abouttwenty-three degrees each side of its equinoctial position, and printed with a representation of one hemisphere of the earth so disposed as to show through the circular opening, and with words descriptive of the seasons so disposed as to appear at appropriate intervals through the openings, D and E, as the plate, 13, is rotated;

the fixed translucent plate, S, tinted with colors representing the zones; and a representation of the sun so placed as to be opposite the equator of the hemisphere when the same is in its equinoctial position.

4. Inan astronomical chart, the frame, A,

:provided with a circular opening, and with the openings, D and E the transparentplate,

"B, pivoted torotate about twenty-three degrees each side of its equinoctial position, and printed with'a representation of one hemisphere of theearth so disposed as to show through the circular opening, and with words descriptive ofthe seasons so disposed as to appear at appropriate intervals through the grees each side of its equinoctial position,-

and printed with a representation of one hemisphere of the earth so disposed as to show through the circular opening, and with words descriptive of the seasons so disposed as to appear at appropriate intervals through the openings, D and E, as the plate, B, is rotated; a representation of the sun so placed as to be opposite the equator of the hemisphere when the same is in its equinoctial position; in combination with a series of translucent plates, 13, so disposed as to appear through the openings in the chart surrounding a second representation of the sun, I, and adapted to show the position of the earth at the different months in the plane of its orbit; together with words descriptive of the months and seasons printed upon the chart, near the said representations of the earth to which they are appropriate.

LEVI \V. YAGGY.

WVitnesses ALOYSIA HELMIOH, ROBERT 0. PAGE. 

